The relative concentrations of various calcium isotopes can be an important diagnostic marker for a variety of medical conditions. For example, the ratio of 44 Ca to 40 Ca in human blood or urine can provide important diagnostic information regarding bone mineral balance, making it possible to track and/or diagnose certain metabolic bone diseases and track the impact of treatments. As a difference example, monitoring bone mineral balance is useful for detecting bone density loss, which may have applications for maintaining health during long space missions. The ability to assess quickly and accurately relative abundance of calcium isotopes in chosen samples also has applications beyond the medical diagnostic fields, for example, in geochemistry, planetary science, climate science, and other fields.
Currently, calcium isotopic analysis is performed using mass-spectrometry, and, specifically, thermal-ionization mass-spectrometry or multiple collector inductively coupled mass-spectrometry. While effective, such techniques provide a typically slow analysis and employ costly equipment that requires sophisticated supporting infrastructure and technical expertise. As a result, conventional methods are generally unsuited for use outside of a laboratory environment.